Parsing error for binary operation.

Rule Set:

```
#(x / 30000, x/50000, x/80000)@(0, 90, 0)!(x)F(x  + 1)
```

Axiom:

```
F(0)
```

Evaluating this axiom in the context of the given ruleset yields an error `Binary operation "x +1" contains invalid number of operands.`
